Sauté thinly sliced onion or shallot in olive oil or butter and add salt and chopped leaves of sage. When browning and translucent, add chopped wild mushrooms, like cèpes, cantharelles, pieds de moutons. Or use a mix of cultivated ones. Sauté for a few minutes, and then add a sweet wine like Madeira. Stew for some 15 minutes or more. Stir in crème fraîche, and serve over rice.